diff --git a/.clangd b/.clangd
index 28b5a38..b03c4bc 100644
--- a/.clangd
+++ b/.clangd
@@ -5,3 +5,6 @@ CompileFlags:
     - -fstrict-volatile-bitfields
     - -fno-tree-switch-conversion
     - -fanalyzer
+    - -ffixed-r2
+    - -ffixed-r3
+    - -ffixed-r4
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index b42d0c9..31187ee 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -35,7 +35,10 @@
 				"files.associations": {
 					"*.S": "avr"
 				},
-				"clangd.path": "/usr/bin/clangd"
+				"clangd.path": "/usr/bin/clangd",
+				"clangd.arguments": [
+					"--compile-commands-dir=${workspaceFolder}/out/build"
+				]
 			}
 		}
 	},